Dialysis system with radio frequency device within a magnet assembly for medical fluid sensing and concentration determination

• US 10,371,775 B2
• Filed: 03/03/2017
• Issued: 08/06/2019
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Jones, Ross Peter, Crnkovich, Martin Joseph, Wang, Fei, Folden, Thomas Irvin, Jensen, Lynn, Kalaskar, Shashikant Dattatraya
• Primary Examiner(s): Brewster, Hayden
• Application Number:
  US15/449,127
• Publication Number:
  US 20170176558A1
• Time in Patent Office: 886 Days
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/1562 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1605 Physical characteristics of the dialysate fluid
• CPC Class Codes: A61M 1/1619 Sampled collection of used dialysate, i.e. obviating the need for recovery of whole dialysate quantity for post-dialysis analysis
• CPC Class Codes: A61M 1/267 used for pumping
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/36222 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/6072 Bar codes
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 2230/20 Blood composition characteristics
• CPC Class Codes: G01N 24/08 by using nuclear magnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/1276 of magnetic particles, e.g. imaging of magnetic nanoparticles G01R33/1269 takes precedence
• CPC Class Codes: G01R 33/302 : Miniaturized sample handling arrangements for sampling small quantities, e.g. flow-through microfluidic NMR chips
• CPC Class Codes: G01R 33/34053 : Solenoid coils; Toroidal coils
• CPC Class Codes: G01R 33/383 : using permanent magnets
• CPC Class Codes: G01R 33/465 : applied to biological material, e.g. in vitro testing
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 50/20 : for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

Claims

1. A dialysis system comprising:

a magnet assembly that generates a magnetic field, the magnet assembly defining an opening;

a radio frequency device disposed in the opening of the magnet assembly, the radio frequency device defining a first cavity configured to receive a first section of a first portion of a cartridge, the first cavity being internal to the radio frequency device, and a second cavity being defined between the radio frequency device and the magnet assembly such that the second cavity is outside of the radio frequency device, the second cavity being configured to receive a second section of the first portion of the cartridge; and

a dialysis fluid pump that is operable to pump dialysis fluid to the first portion of the cartridge when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity,

wherein the radio frequency device is operable to receive radio frequency energy generated by excited atoms in the dialysis fluid in the first portion of the cartridge when the first and second sections of the first portion of the cartridge are disposed in the first and second cavities, respectively, and dialysis fluid has been pumped to the first portion of the cartridge.

2. The dialysis system of claim 1, wherein the radio frequency device is further operable to apply radio frequency energy to dialysis fluid in the first portion of the cartridge to excite the atoms in the dialysis fluid in the first portion of the cartridge.

3. The dialysis system of claim 2, wherein the radio frequency device is a radio frequency coil.

4. The dialysis system of claim 1, further comprising a controller in communication with the radio frequency device, the controller being configured to determine a concentration of a substance in the dialysis fluid based on the received radio frequency energy generated by the excited atoms in the dialysis fluid in the first portion of the cartridge.

5. The dialysis system of claim 4, wherein the controller is configured to determine the concentration of the substance in the dialysis fluid as a function of (i) the radio frequency energy generated by the excited atoms in the dialysis fluid in the first portion of the cartridge and (ii) a volume of the first portion of the cartridge.

6. The dialysis system of claim 1, further comprising the cartridge.

7. The dialysis system of claim 6, wherein the first section of the first portion of the cartridge defines a first meandering fluid passageway, and the first portion of the cartridge is configured to be disposed within the opening of the magnet assembly.

8. The dialysis system of claim 7, wherein the cartridge is configured such that the first meandering fluid passageway is disposed in the first cavity outside the radio frequency device when the first portion of the cartridge is disposed in the opening of the magnet assembly.

9. The dialysis system of claim 6, wherein the second section of the first portion of the cartridge defines a second meandering fluid passageway.

10. The dialysis system of claim 9, wherein the cartridge defines a fluid inlet port via which the dialysis fluid enters the cartridge, the fluid inlet port having a first flow area and the second meandering fluid passageway having a second flow area that is smaller than the first flow area.

11. The dialysis system of claim 6, wherein the cartridge comprises a second portion configured to be positioned outside the radio frequency device when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity.

12. The dialysis system of claim 11, wherein the second portion of the cartridge is configured to be positioned at least partially outside the magnet assembly when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity.

13. The dialysis system of claim 11, wherein the second portion of the cartridge defines a fluid passageway that bypasses the first portion of the cartridge.

14. The dialysis system of claim 13, wherein the fluid passageway of the second portion of the cartridge is a substantially straight fluid passageway.

15. The dialysis system of claim 1, wherein the dialysis fluid pump is a blood pump.

16. The dialysis system of claim 1, wherein the dialysis fluid pump is a dialysate pump.